From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH v3 01/10] iommu: Add helper to get minimal page size of domain Date: Mon, 29 Apr 2019 11:55:54 +0100 Message-ID: <05eca601-0264-8141-ceeb-7ef7ad5d5650@arm.com> References: <20190421011719.14909-1-baolu.lu@linux.intel.com> <20190421011719.14909-2-baolu.lu@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190421011719.14909-2-baolu.lu@linux.intel.com> Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Lu Baolu , David Woodhouse , Joerg Roedel Cc: ashok.raj@intel.com, jacob.jun.pan@intel.com, alan.cox@intel.com, kevin.tian@intel.com, mika.westerberg@linux.intel.com, pengfei.xu@intel.com, Konrad Rzeszutek Wilk , Christoph Hellwig , Marek Szyprowski , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org On 21/04/2019 02:17, Lu Baolu wrote: > This makes it possible for other modules to know the minimal > page size supported by a domain without the knowledge of the > structure details. > > Signed-off-by: Lu Baolu > --- > include/linux/iommu.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index a5007d035218..46679ef19b7e 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -377,6 +377,14 @@ static inline void iommu_tlb_sync(struct iommu_domain *domain) > domain->ops->iotlb_sync(domain); > } > > +static inline unsigned long domain_minimal_pgsize(struct iommu_domain *domain) > +{ > + if (domain && domain->pgsize_bitmap) > + return 1 << __ffs(domain->pgsize_bitmap); Nit: this would probably be more efficient on most architectures as: if (domain) return domain->pgsize_bitmap & -domain->pgsize_bitmap; I'd also suggest s/minimal/min/ in the name, just to stop it getting too long. Otherwise, though, I like the idea, and there's at least one other place (in iommu-dma) that can make use of it straight away. Robin. > + > + return 0; > +} > + > /* PCI device grouping function */ > extern struct iommu_group *pci_device_group(struct device *dev); > /* Generic device grouping function */ > @@ -704,6 +712,11 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) > return NULL; > } > > +static inline unsigned long domain_minimal_pgsize(struct iommu_domain *domain) > +{ > + return 0; > +} > + > #endif /* CONFIG_IOMMU_API */ > > #ifdef CONFIG_IOMMU_DEBUGFS > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21533C43219 for ; Mon, 29 Apr 2019 10:58:58 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E5CF420673 for ; Mon, 29 Apr 2019 10:58:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E5CF420673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 0773B1F0A; Mon, 29 Apr 2019 10:58:44 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id DB7431EF8 for ; Mon, 29 Apr 2019 10:56:01 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 8C638608 for ; Mon, 29 Apr 2019 10:56:01 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5756380D; Mon, 29 Apr 2019 03:56:01 -0700 (PDT) Received: from [10.1.196.75] (e110467-lin.cambridge.arm.com [10.1.196.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 068C83F5AF; Mon, 29 Apr 2019 03:55:58 -0700 (PDT) Subject: Re: [PATCH v3 01/10] iommu: Add helper to get minimal page size of domain To: Lu Baolu , David Woodhouse , Joerg Roedel References: <20190421011719.14909-1-baolu.lu@linux.intel.com> <20190421011719.14909-2-baolu.lu@linux.intel.com> From: Robin Murphy Message-ID: <05eca601-0264-8141-ceeb-7ef7ad5d5650@arm.com> Date: Mon, 29 Apr 2019 11:55:54 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190421011719.14909-2-baolu.lu@linux.intel.com> Content-Language: en-GB Cc: kevin.tian@intel.com, ashok.raj@intel.com, Konrad Rzeszutek Wilk , alan.cox@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, pengfei.xu@intel.com, jacob.jun.pan@intel.com, mika.westerberg@linux.intel.com, Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="UTF-8"; format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Message-ID: <20190429105554.kvy5my6lojS7AavU5PTdQPfPoFyIckiMgh9xAXIEFvs@z> On 21/04/2019 02:17, Lu Baolu wrote: > This makes it possible for other modules to know the minimal > page size supported by a domain without the knowledge of the > structure details. > > Signed-off-by: Lu Baolu > --- > include/linux/iommu.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index a5007d035218..46679ef19b7e 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -377,6 +377,14 @@ static inline void iommu_tlb_sync(struct iommu_domain *domain) > domain->ops->iotlb_sync(domain); > } > > +static inline unsigned long domain_minimal_pgsize(struct iommu_domain *domain) > +{ > + if (domain && domain->pgsize_bitmap) > + return 1 << __ffs(domain->pgsize_bitmap); Nit: this would probably be more efficient on most architectures as: if (domain) return domain->pgsize_bitmap & -domain->pgsize_bitmap; I'd also suggest s/minimal/min/ in the name, just to stop it getting too long. Otherwise, though, I like the idea, and there's at least one other place (in iommu-dma) that can make use of it straight away. Robin. > + > + return 0; > +} > + > /* PCI device grouping function */ > extern struct iommu_group *pci_device_group(struct device *dev); > /* Generic device grouping function */ > @@ -704,6 +712,11 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) > return NULL; > } > > +static inline unsigned long domain_minimal_pgsize(struct iommu_domain *domain) > +{ > + return 0; > +} > + > #endif /* CONFIG_IOMMU_API */ > > #ifdef CONFIG_IOMMU_DEBUGFS > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu